Monitoring protein in herd of dairy cows in Sergipe

Abstract

The object this research was to evaluate the urea plasma urea nitrogen (PUN) in different dairy herds in order to obtain a diagnosis of levels of dietary protein utilization of lactating cows and to relate these levels with economic and productive aspects. The experiment was conducted in 25 rural properties with the exploitation of dairy cattle in the municipality of Nossa Senhora da Glória - SE. Blood samples were collections in five cows per properties, every 30 days, over a period of three months to determining of the NUP. Then, were selected 10 properties, among the 25 evaluated, which featured greater control to analyze zootechnical, to analyze possible PUN associations with nutritional, productive and reproductive parameters, as well as evaluating the milk income’s commitment (CRL) with concentrated supplementation. The experimental design was completely randomized split plot in time. Were obtained variations of PUN between 6.97 and 29.2 mg/dL (P <0.05) and overall average of 15.46 mg/dL between the properties. Of these, only 37.33% presented within the standards, being PUN found that increasing levels of crude protein (CP) in the diet resulted in the elevation of the NUP values and reduced reproductive efficiency. It was observed an average commitment of 38.17% of income from milk (CRL), with the use of concentrated, between the properties. Under the conditions of this research, there was wide variation in the levels of PUN who had since low values, indicating a possible fault in the nutritional management to levels above those recommended, suggesting an excess of protein offered to the animals or nutritional imbalance in the ratio of protein/energy. These data demonstrate the need for a local service guiding for better nutritional management of these herds.